feat: add Table.from_records and Table.from_file factory methods

[tbhb]

Summary

• Add Table.from_records(path, records, key) for creating tables with initial data
• Add Table.from_file(path) for loading existing files with automatic key detection
• Update README quick start and examples to use the new factory methods

Test plan

• Unit tests for both factory methods (30 tests)
• Type checking passes
• Linting passes

[codspeed-hq]

CodSpeed Performance Report

Merging #14 will not alter performance

_{Comparing factory (f284789) with main (46d2228)}

Summary

✅ 173 untouched
⏩ 1 skipped¹

Footnotes

1. 1 benchmark was skipped, so the baseline result was used instead. If it was deleted from the codebase, click here and archive it to remove it from the performance reports. ↩

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.

📢 Thoughts on this report? Let us know!